Math Chapter Wise Limit, Continuity And Differentiability Of Function Of Two Variables And Partial Differentiation English MCQ UP PCS (Pre) 1997 Q.The function f(x,y) may have a maximum or minimum at a point, if at that point: A2 2 2 2 2 2 f f f. 0 x y xdy ∂ ∂ ∂ − > ∂ ∂ ∂ B2 2 2 2 2 2 f f f. 0 x y xdy ∂ ∂ ∂ − < ∂ ∂ ∂ C2 2 2 2 2 2 f f f. 0 x y xdy ∂ ∂ ∂ − = ∂ ∂ ∂ DNone of these Show answer Correct answer: None of these